canyonclassics

Looking for some input on a roll bar that popped up on me. The top system was previously 100% working correctly and I was having some issues with control units on a few other r129 cars I have in inventory. I decided to play musical control units to test which ones I have are still good and I plugged one in and the roll bar popped up when I plugged in the harness. I cant for the life of me get it to retract now. Have checked fuses (fuse 3 in trunk was blown...I replaced it) I have tried holding roll bar switch up to re-latch, no luck. Soft top will work if I push and hold bar down, but it pops back up if I let go of bar. I have asked an independent MB tech I know and he claims that because of the short there is a ram that pops almost like an airbag, and now much be replaced....does this sound right? I have looked everywhere and have heard nobody say anything about that. Seems like if the bar pops up it can be re-latched. I was in the car when the bar popped and I didnt hear anything pop, was relatively quiet when it jumped up. Thanks to anybody who can lend some advice.

lynns

Do a Roll Over Bar Switch Reset. Hold the Roll Over Bar switch in the UP position for at 10+ seconds and listen for a small Click reset. Then the switch should work properly after that.

ccarchia

I have a 1991 300sl roll bar stuck down
I hit the up switch i here a click but nothing
top works perfect any clues
the roll bar is stuck down
I tried holding the switch in for up to 30 sec
and nothing any help is appreciate thanks

lynns

Check trunk fuse #3 for corrosion, etc. You may find that you need to upgrade your fuses to an Aftermarket Copper / Brass Fuse FWIW, 1990 to 1993 has a separate roll-over bar controller if it was built prior to 11/92 VIN 083890

TheSaint

THIS IS A EASY FIX! Hold in, press the button for the roll bar in the up position for 5 seconds(pressed in for 5 to 8 seconds and it will reset the roll bar)and let go.
Press the button down and i am sure the roll bar will work as usual

lynns

I would hope he already read and tried post #2 above.

TheSaint

I just saw the question and answered so i was a bit fast on the trigger

When this happend to my car some years ago i ohoned my local Mercedes dealer/repair shop and they told me they had to take apart everything regarding to the roll bar.
I had a feeling that they usually only work on C and E class and so on SL class

So i phoned another MB dealer i knew did a lot of work on MB SL`s and got the correct answer about holding in the switch

I am sure if i have delivered my car to my local MB shop they would have started to tear apart the roll bar..

Glad i did take the phone call to the MB dealer that usuallly works on SL cars when the roll bar got stuck in the up position

ccarchia

the roll bar is stuck down held the roll bar button in for 30 sec still nothing
changed the fuse and no luck any clues

Kenny Amado

Howdy folks. l hope i can jump in, and someone can make sense of my ramblings lol

Ive been looking over quite a few forums to try to find the answer to my problem.

Ive had a few benz over the years so Im not a stranger to the Germans sick sense of humor when it comes to these cars.

I bought my 91 500sl about 4 months ago. Ive been slowly bringing her back to life. She belonged to a fellow that had no clue what he was doing. Good news he sold it for a steal.

I bought the car knowing that the soft top didnt work. He didnt know it needed hydraulic fluid so, as I suspected it was low on fluid, I topped it off, and the system still didn't work. I checked the fuses they were all blown so I replaced all of them with new ones. That's when the hydraulic locks above the windshield started leaking. I removed the locks and rebuild the hydraulic pumps, so the leak stopped.

The top however is still not getting any life to it. When I hooked up the OBD1 reader to socket 7. I get a constant light. No flashed, no ability to reset it. just a constant light, and I haven't seen anyone that has had this issue so far.

When I hook up the OBD1 reader to socket 9 for the roll bar, it shows no fault. Socket 10 also shows no fault for the soft top.

The roll bar is also stuck in the up position, I took a turn too fast and pop goes the weasel. Its like a damn jack in the box, you know what its like but it still gives you a heart attack each time it jumps up.

The roll bar light was on for a while. The last few days it has been off. I have help the up button to reset the roll bar, and nothing, All of the hydraulic components look clean and good. No leaks. The roll bar just doesnt have any life to it. I know the two are linked together. Any Ideas on why the OBD1 reader is showing a constant light in socket seven. And any trouble shooting steps would be much appreciated.

I can rebuild all the internal workings of the hydraulic pistons no problem, but the electrical side of this had me stumped.

Theres a lot of info on how to get the roll bar to go up, not to much on how to get it to go down.

bobterry99

Socket #7 is for the roll bar, and #9 is for ADS suspension, which I presume you don't have.

Try reading from sockets #3, #6, #11, #12, and #14. If you can read from neither of these as well, then I am suspicious of the reader you are using or your technique.

Codes aside, there are a few troubleshooting steps I would take. Presuming the power windows work fine, I would raise both. Now try to operate the top from its fully open or closed position. The windows should lower. If they do, now I would have someone operate the switch while you place your fingers on the roof pump control relay. You should feel its coil energizing.

lynns

you posted your 1991 SL to this 1999 SL thread. Please realize that the design is different than 1990 to 1993 that has a separate roll-over bar controller if it was built prior to 11/92 VIN 083890. "Now start your Search."

BTW, hello Bob Terry. Hope all is well.

lynns

Please feel free to learn about your new car at
https://www.benzworld.org/forums/r12...ontroller.html

PeterJ500

Hi guys n galz... 1st, this happened to me once 3-4 years ago and I forget how I fixed it back then...
Vaguely, I got a tip from an mbw forum and I think it was a fairly easy mechanical fix ???

This time, the roll bar switch had stopped working about 6 months ago (The car gets driven maybe 2-3 times a month)...
The bar was down so I didn't worry about chasing up the issue, I just assumed that the switch gave up...

So... the bar popped up when i drove over a bit of a hump on the road a couple weeks ago and it stayed up. Again I wasn't too worried as it's winter now here in Australia But today is such a beaut day, I decided to put the roof down... Other than lowering the windows, the roof does not respond after that... I assume the car thinks it has rolled over ... but still hammers on... lol

As the switch does not work, I can't lower the bar with the 10+ second trick you guys mention here... and I can't recall how I got it down last time...

Any ideas anyone ???

PS I will bookmark this page but I'm not sure if that will bring me back here again, so if you could please email any suggestions / workarounds, I would greatly appreciate it peterj1000@hotmail.com.

bobterry99

I'm familiar with lowering the bar manually on an R230, and I presume it is the same with the 129.

Remove the coverings on the rear wall to expose the mechanical supports for the roll bar. On both the left and right support you will probably notice a spring loaded "lock" of sorts which engages the roll bar to hold it in position. Use a tool of some sort to simultaneously release the lock on both sides while someone else pushes the roll bar down.

PeterJ500

thanks bob terry,
it rings a bell (i've done so much other work on it over the time that simply forgot this one)...
i'll give it a go on the next not so cold and not so wet day, see how it goes ... cheers

EDITED JULY 14 2019
It is so simple, Stripped it down for nothing, just like last time hahaha I feel like an Idiot...
OK, the 1991, which is the only one I can speak for, operates the roll bar up/down as the soft top raises / lowers.

SO, if the Roll Bar is Stuck UP and you can't lower it from the switch:
1. Ignition ON so the electrics work
2. Engine NOT RUNNING so there is no hydraulic pressure
3. Hold the roof switch toward DOWN (you hear the roll bar ratchet locks Click)
4. While holding the roof switch Down, Reach over and gently Push the Roll bar all the way Down until it locks in place (you will feel / hear the click)

... If the roof is not working. or stopping at various positions, you may have caused some confusion to the roof and/or bar modules, especially if you have been trying manual release of the bar or the roof... as I did...
how I fix that:
5. Make sure the roof is Fully closed with all 6 latches locked into place, manually if necessary.
6. Disconnect the battery, I do both terminals
7. Unplug Both plugs from the Roof Module.
8. Give it a minute to forget the recent position switch sequence.
9. Re-connect the Roof Module, then the battery.

If there are no other issues the roof will work fine...

I hope this helps

.

steveinoz

Just read about holding the 'up' button for the rollbar when it deployed over a bump & wouldn't drop. That fixes it. Held 'up' button for around 10 secs, then pressed 'down' button - fixed. There's a click when you hold the up button.
I'm new here & was wondering about the electrical issues. This car, 1995 500SL - 4 speed. It stutters & misses under acceleration from standing to around 20mph then clears. Same at traffic lights, almost sounds like it's going to stall but so far hasn't. I know about the wiring harness in these things but also believe the distributor caps hold moisture & this could be the issue. Assuming it's not the harness, has anyone got a fix (permanent) for the dizzy issue? I know in the '96 models it wasn't an issue..
Best
Steve